//http://www.zdnet.com/blog/burnette/how-to-use-multi-touch-in-android-2-part-5-implementing-the-drag-gesture/1789
// pich zoom an image 

package org.example.touch;

import org.example.touch.R;
import android.app.Activity;
import android.graphics.Matrix;
import android.graphics.PointF;
import android.os.Bundle;
import android.util.FloatMath;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.ImageView;

public class Touch extends Activity implements OnTouchListener {
	private static final String TAG = "Touch";
	private static final String TAG_ZOOM = "ZOOM_SCALE";
	Matrix matrix = new Matrix();
	Matrix savedMatrix = new Matrix();

	// We can be in one of these 3 states
	static final int NONE = 0;
	static final int DRAG = 1;
	static final int ZOOM = 2;
	static final int ELASTIC = 3;
	int mode = NONE;
	PointF start = new PointF();
	PointF mid = new PointF();
	PointF upos = new PointF(0, 0);
	PointF oldpos = new PointF(0, 0);

	float oldDist = 1f;
	float uscale = 1.0f;
	float oldscale = 1.0f;

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		ImageView view = (ImageView) findViewById(R.id.imageView);
		view.setOnTouchListener(this);
	}

	@Override
	public boolean onTouch(View v, MotionEvent event) {
		ImageView view = (ImageView) v;

		// Dump touch event to log
		dumpEvent(event);

		// Handle touch events here...
		switch (event.getAction() & MotionEvent.ACTION_MASK) {

		case MotionEvent.ACTION_DOWN:
			savedMatrix.set(matrix);
			start.set(event.getX(), event.getY());
			Log.d(TAG, "mode=DRAG");
			mode = DRAG;
			break;

		case MotionEvent.ACTION_UP:
			//view.get
			Log.d(TAG, "getIntrinsicHeight = " + view.getDrawable().getIntrinsicHeight());
			Log.d(TAG, "getIntrinsicWidth = " + view.getDrawable().getIntrinsicWidth());
			/*
			 * if (upos * oldscale > 2.0f) { matrix.set(savedMatrix); } else {
			 * uscale *= oldscale; //Log.d(TAG_ZOOM, "uscale = " + uscale); }
			 * oldpos.set(0, 0); break;
			 */

		case MotionEvent.ACTION_POINTER_UP:
			if (uscale * oldscale > 4.0f || uscale * oldscale < 0.2f ) {
				matrix.set(savedMatrix);
/*				int numBins = 100; //animation zoom out
				float binSize = (uscale * oldscale-uscale) / numBins;
						
				for (int i=0; i<numBins ;i++){
					float scale = uscale * oldscale - binSize ;
					matrix.postScale(scale, scale, mid.x, mid.y);
					view.setImageMatrix(matrix);
				}*/
						
			} else {
				uscale *= oldscale;
				Log.d(TAG_ZOOM, "uscale = " + uscale);
			}
			oldscale = 1f;
			mode = NONE;
			break;

		case MotionEvent.ACTION_MOVE:
			if (mode == DRAG) {
				matrix.set(savedMatrix);
				matrix.postTranslate(event.getX() - start.x, event.getY()
						- start.y);
				// oldpos.set(event.getX() - start.x, event.getY() - start.y);

			} else if (mode == ZOOM) {
				float newDist = spacing(event);
				Log.d(TAG, "newDist=" + newDist);

				if (newDist > 10f) {
					matrix.set(savedMatrix);
					float scale = newDist / oldDist;
					oldscale = scale;
					matrix.postScale(scale, scale, mid.x, mid.y);
				}
			}
			break;

		case MotionEvent.ACTION_POINTER_DOWN:
			if (mode != ZOOM) {
				oldDist = spacing(event);
				Log.d(TAG, "oldDist=" + oldDist);
				if (oldDist > 10f) {
					savedMatrix.set(matrix);
					midPoint(mid, event);
					mode = ZOOM;
					Log.d(TAG, "mode=ZOOM");
				}
			}
			break;
		}

		// Perform the transformation
		view.setImageMatrix(matrix);

		return true; // indicate event was handled
	}

	private float spacing(MotionEvent event) {
		float x = event.getX(0) - event.getX(1);
		float y = event.getY(0) - event.getY(1);
		return FloatMath.sqrt(x * x + y * y);
	}

	private void midPoint(PointF point, MotionEvent event) {
		float x = event.getX(0) + event.getX(1);
		float y = event.getY(0) + event.getY(1);
		point.set(x / 2, y / 2);
	}

	/** Show an event in the LogCat view, for debugging */
	private void dumpEvent(MotionEvent event) {
		String names[] = { "DOWN", "UP", "MOVE", "CANCEL", "OUTSIDE",
				"POINTER_DOWN", "POINTER_UP", "7?", "8?", "9?" };
		StringBuilder sb = new StringBuilder();
		int action = event.getAction();
		int actionCode = action & MotionEvent.ACTION_MASK;
		sb.append("event ACTION_").append(names[actionCode]);
		if (actionCode == MotionEvent.ACTION_POINTER_DOWN
				|| actionCode == MotionEvent.ACTION_POINTER_UP) {
			sb.append("(pid ").append(
					action >> MotionEvent.ACTION_POINTER_ID_SHIFT);
			sb.append(")");
		}
		sb.append("[");
		for (int i = 0; i < event.getPointerCount(); i++) {
			sb.append("#").append(i);
			sb.append("(pid ").append(event.getPointerId(i));
			sb.append(")=").append((int) event.getX(i));
			sb.append(",").append((int) event.getY(i));
			if (i + 1 < event.getPointerCount())
				sb.append(";");
		}
		sb.append("]");
		Log.d(TAG, sb.toString());
	}
}
